first kron4 a cake thompson joins us live. they're letting us know where federal but authorities are in the investigation. >> federal authorities are looking for information. dave heard reports in claims of people in the neighborhood smell gas . they're asking one in december know whoever reported smelling gas to please contact them. they're also looking into it anyone who might have dead vegetation in their yard, that could be a clue there was a ghastly. and they're also looking for people to give on that information. they're asking for cell phone video out surveillance video, anything out of the ordinary that could help with this investigation. because they still have clearly not been able to determine what caused the blast. today they said they bought an additional investigators to help them out. >> we have added two additional staffers to help us with the work. when we have started to do, document the damage, document the fire, the heat, the fatalities the injuries. the more that we can document the exact location and the